Flavan-containing cells delimit Frankia-infected compartments in Casuarina glauca nodules

• Published in: Plant physiology (Bethesda) Vol. 121; no. 1; pp. 113 - 122
• Main Authors: Laplaze, L, Gherbi, H, Frutz, T, Pawlowski, K, Franche, C, Macheix, J.J, Auguy, F, Bogusz, D, Duhoux, E
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Physiologists 01-09-1999
• Subjects: Actinomycetales - growth & development; Acyltransferases - genetics; Amino Acid Sequence; amino acid sequences; Casuarina glauca; Catechin - analogs & derivatives; Catechin - analysis; Cell walls; chemical constituents of plants; Chromatography, High Pressure Liquid; colonization; complementary DNA; cortex; EPS; flavans; Flavonoids; Flavonoids - analysis; Frankia; Gene Expression Regulation, Plant; Genes, Plant - genetics; histochemistry; Histocytochemistry; Hydrolyzable Tannins - analysis; In Situ Hybridization; Infections; Laboratorium voor Moleculaire biologie; Laboratory of Molecular Biology; Magnoliopsida - chemistry; Magnoliopsida - cytology; Magnoliopsida - genetics; Magnoliopsida - microbiology; messenger RNA; Molecular Sequence Data; naringenin-chalcone synthase; Nodules; nucleic acid hybridization; nucleotide sequences; Periderm; phenolic compounds; Phenols - analysis; Plant roots; Plant Roots - anatomy & histology; Plant Roots - chemistry; Plant-Microbe and Plant-Insect Interactions; Plants; quantitative analysis; Reagents; RNA, Messenger - analysis; RNA, Messenger - genetics; root nodules; roots; Symbiosis; Tannins
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.121.1.113

We investigated the involvement of polyphenols in the Casuarina glauca-Frankia symbiosis. Histological analysis revealed a cell-specific accumulation of phenolics in C. glauca nodule lobes, creating a compartmentation in the cortex. Histochemical and biochemical analyses indicated that these phenolic compounds belong to the flavan class of flavonoids. We show that the same compounds were synthesized in nodules and uninfected roots. However, the amount of each flavan was dramatically increased in nodules compared with uninfected roots. The use of in situ hybridization established that chalcone synthase transcripts accumulate in flavan-containing cells at the apex of the nodule lobe. Our findings are discussed in view of the possible role of flavans in plant-microbe interactions.